目的 探讨多层螺旋CT在评价颈动脉斑块特征中的价值。 方法 回顾性分析2011年7月－10月132例行CT颈部血管造影患者的影像资料。对颈动脉斑块特征进行评价，重建方法包括多层面重建、容积再现技术、最大密度投影及曲面重建。 结果 132例患者中，80例检出颈动脉斑块，最常出现钙化斑块的部位为海绵窦段和床突上段，右侧海绵窦段52例（65.0%）、左侧海绵窦段49例（61.3%），右床突上段37例（46.3%）、左侧床突上段30例（37.5%）。最常出现软斑块的部位为双侧颈总动脉，均为12例（15.0%）。最常出现混合斑块的部位为颈总动脉，右侧颈总动脉9例（11.3%）、左侧颈总动脉12例（15.0%）。颈动脉最容易轻度狭窄294处（294/1 440，20.4%），中、重度狭窄少见，分别为8处（8/1 440，0.5%）和6处（6/1 440，0.4%）。颈部动脉血管斑块最易出现钙化，总计249处（249/1 440，17.3%），其次是软斑块和混合斑块，均为39处（39/1 440，2.7%）。 结论 多层螺旋CT可准确评价颈动脉斑块特征。
【摘要】 目的 探讨双源CT在诊断肺栓塞中的价值。 方法 2008年5月－2010年12月纳入50例可疑肺栓塞患者，使用双源CT进行肺动脉血管增强扫描，对图像行三维重建，分析栓塞部位、栓子形态、肺内、心脏及胸腔改变等。 结果 44例确诊肺栓塞，发现肺栓塞共260处，最常见于右肺下叶动脉28例（63.0%），其次于右肺动脉22例（50.0%）、左肺下叶动脉19例（43.2%）；15例（34.1%）累及亚段肺动脉；右肺动脉受累较左肺动脉常见（Plt;0.05）。39例系急性肺栓塞（88.6%），5例系慢性肺栓塞（11.4%）。 结论 双源CT扫描速度快，空间分辨率高，可以准确显示肺栓塞部位，并且可以同时评价胸腔、肺内及心脏的变化。在临床上，双源CT可以作为肺栓塞的首选检查。【Abstract】 Objective To explore the value of dual-source CT in diagnosing pulmonary embolism. Methods From May 2008 to December 2010, 50 patients who were suspected of pulmonary embolism were included, and pulmonary angiography was performed on these patients by dual-source CT. The obtained images were reconstructed with three dimensional technique to analyze the location and shape of the embolism, and lesions affecting the lung, heart and thoracic cavity. Results A total of 44 patients wiht pulmonary embolism with 260 affected branches of arteries were confirmed by CT angiography. The most common affecting artery was the right lower pulmonary artery(28/44,63.0%), which was followed by the right pulmonary artery (22/44,50.0%) and the left lower pulmonary artery(19/44,43.2%). Segmental and subsegmental pulmonary arteries were involved in 15 patients (15/44, 34.1%). Pulmonary artery embolism involves the right pulmonary arteries more frequently than the left pulmonary arteries (P＜0.05).Acute pulmonary embolism was found in 39 cases(39/44, 88.6%), while chronic pulmonary embolism was found in 5(5/44, 11.4%). Conclusions Dual-source CT with fast scanning speed and high spatial resolution can demonstrate the exact site of the pulmonary embolism and evaluate the lesions of thoracic cavity, lung and heart. In clinical practice, dual-source CT could be the preferred choice in diagnosing pulmonary embolism.
This paper aims to explore the feasibility of building a finite element model of left atrial diverticulum (LAD) using reverse engineering software based on computed tomography (CT) images. The study was based on a three-dimensional cardiac CT images of a atrial fibrillation patient with LAD. The left atrium and LAD anatomical features were accurately reproduced by using Geomagic Studio 12 and Mimics 15 reverse engineering software. In addition, one left atrial model with LAD and one without LAD were created with ANSYS finite element analysis software, and the validity of the two models were verified. The results show that it is feasible to establish the LAD finite element model based on cardiac three-dimensional CT images using reverse engineering software. The results of this paper will lay a theoretical foundation for further hemodynamic analysis of LAD.
ObjectiveTo explore the impact of different monochromatic reconstruction on image quality of early lesions of coronavirus disease 2019 (COVID-19).MethodsThe chest spectral CT images of 11 patients confirmed as COVID-19 in West China Hospital of Sichuan University between January and February 2020 were retrospectively analyzed. A total of 34 inflammatory lesions were found in the 11 cases. Seven groups of images were reconstructed from the raw data for each patient, including the conventional polychromatic image and different monochromatic images of 40-140 keV (with intervals of 20 keV). CT and standard deviation (SD) values of all lesions were measured to calculate the signal-noise ratio (SNR) and contrast-noise ratio (CNR). The image quality was subjectively scored by two radiologists, and the differences in image quality among different monochromatic groups and the polychromatic group were compared.ResultsWith the increase of X-ray energy, the CT values and SD values of reconstructed images in monochromatic groups gradually decreased, and the SNRs and CNRs gradually increased, and the differences between adjacent two groups were all statistically significant (P<0.001). In the range of 80-140 keV, the SD values of different monochromatic groups were lower than that of the polychromatic group, and the SNRs and CNRs were higher than those of the polychromatic group, and the pairwise comparison results showed statistically significant differences (P<0.001). The 120 keV-reconstructed image had the highest subjective score, and the difference from that of the polychromatic image was statistically significant (P<0.05).ConclusionsDifferent monochromatic reconstruction of spectral CT can significantly reduce the image noise in early COVID-19 lesions, and improve the image quality. Combining subjective and objective evaluation of images, the 120 keV-reconstructed monochromatic image shows the best early lesions of COVID-19 and is of great significance for early clinical screening.
ObjectiveElectrospinning technique was used to manufacture polycaprolactone (PCL)/collagen typeⅠ nanofibers orientated patches and to study their physical and chemical characterization, discussing their feasibility as synthetic patches for rotator cuff repairing.MethodsPCL patches were prepared by electrospinning with 10% PCL electrospinning solution (control group) and PCL/collagen typeⅠorientated nanofibers patches were prepared by electrospinning with PCL electrospinning solution with 25% collagen type Ⅰ(experimental group). The morphology and microstructure of the two patches were observed by gross and scanning electron microscopy, and the diameter and porosity of the fibers were measured; the mechanical properties of the patches were tested by uniaxial tensile test; the composition of the patches was analyzed by Fourier transform infrared spectroscopy; and the contact angle of the patch surface was measured. Two kinds of patch extracts were co-cultured with the third generation of rabbit tendon stem cells. Cell counting kit 8 (CCK-8) was used to detect the toxicity and cell proliferation of the materials. Normal cultured cells were used as blank control group. Rabbit tendon stem cells were co-cultured with the two patches and stained with dead/living cells after 3 days of in vitro culture, and laser confocal scanning microscopy was used to observe the cell adhesion and activity on the patch.ResultsGross and scanning electron microscopy showed that the two patch fibers were arranged in orientation. The diameter of patch fibers in the experimental group was significantly smaller than that in the control group (t=26.907, P=0.000), while the porosity in the experimental group was significantly larger than that in the control group (t=2.506, P=0.032). The tensile strength and Young’s modulus of the patch in the experimental group were significantly higher than those in the control group (t=3.705, P=0.029; t=4.064, P=0.034). Infrared spectrum analysis showed that PCL and collagen type Ⅰ were successfully mixed in the experimental group. The surface contact angle of the patch in the experimental group was (73.88±4.97)°, which was hydrophilic, while that in the control group was (128.46±5.10) °, which was hydrophobic. There was a significant difference in the surface contact angle between the two groups (t=21.705, P=0.002). CCK-8 test showed that with the prolongation of culture time, the cell absorbance (A) value increased gradually in each group, and there was no significant difference between the experimental group and the control group at each time point (P>0.05). Laser confocal scanning microscopy showed that rabbit tendon stem cells could adhere and grow on the surface of both patches after 3 days of culture. The number of cells adhered to the surface of the patches in the experimental group was more than that in the control group, and the activity was better.ConclusionPCL/ collagen type Ⅰ nanofibers orientated patch prepared by electrospinning technology has excellent physical and chemical properties, cell adhesion, and no cytotoxicity. It can be used as an ideal scaffold material in tendon tissue engineering for rotator cuff repair in the future.
Objective To manufacture a poly (lactic-co-glycolic acid) (PLGA) scaffold by low temperature deposition three-dimensional (3D) printing technology, prepare a PLGA/decellularized articular cartilage extracellular matrix (DACECM) cartilage tissue engineered scaffold by combining DACECM, and further investigate its physicochemical properties. Methods PLGA scaffolds were prepared by low temperature deposition 3D printing technology, and DACECM suspensions was prepared by modified physical and chemical decellularization methods. DACECM oriented scaffolds were prepared by using freeze-drying and physicochemical cross-linking techniques. PLGA/DACECM oriented scaffolds were prepared by combining DACECM slurry with PLGA scaffolds. The macroscopic and microscopic structures of the three kinds of scaffolds were observed by general observation and scanning electron microscope. The chemical composition of DACECM oriented scaffold was analyzed by histological and immunohistochemical stainings. The compression modulus of the three kinds of scaffolds were measured by biomechanical test. Three kinds of scaffolds were embedded subcutaneously in Sprague Dawley rats, and HE staining was used to observe immune response. The chondrocytes of New Zealand white rabbits were isolated and cultured, and the three kinds of cell-scaffold complexes were prepared. The growth adhesion of the cells on the scaffolds was observed by scanning electron microscope. Three kinds of scaffold extracts were cultured with L-929 cells, the cells were cultured in DMEM culture medium as control group, and cell counting kit 8 (CCK-8) was used to detect cell proliferation. Results General observation and scanning electron microscope showed that the PLGA scaffold had a smooth surface and large pores; the surface of the DACECM oriented scaffold was rough, which was a 3D structure with loose pores and interconnected; and the PLGA/DACECM oriented scaffold had a rough surface, and the large hole and the small hole were connected to each other to construct a vertical 3D structure. Histological and immunohistochemical qualitative analysis demonstrated that DACECM was completely decellularized, retaining the glycosaminoglycans and collagen typeⅡ. Biomechanical examination showed that the compression modulus of DACECM oriented scaffold was significantly lower than those of the other two scaffolds (P<0.05). There was no significant difference between PLGA scaffold and PLGA/DACECM oriented scaffold (P>0.05). Subcutaneously embedded HE staining of the three scaffolds showed that the immunological rejections of DACECM and PLGA/DACECM oriented scaffolds were significantly weaker than that of the PLGA scaffold. Scanning electron microscope observation of the cell-scaffold complex showed that chondrocytes did not obviously adhere to PLGA scaffold, and a large number of chondrocytes adhered and grew on PLGA/DACECM oriented scaffold and DACECM oriented scaffold. CCK-8 assay showed that with the extension of culture time, the number of cells cultured in the three kinds of scaffold extracts and the control group increased. There was no significant difference in the absorbance (A) value between the groups at each time point (P>0.05). Conclusion The PLGA/DACECM oriented scaffolds have no cytotoxicity, have excellent physicochemical properties, and may become a promising scaffold material of tissue engineered cartilage.